A follow-up study of extremely low birth weight infants at four to eleven years of age

Abstract

Objective To analyze the relationship between the incidence of complications and disease condition during hospitalization in severe preterm infants after birth, and to understand the situation and problems in treatment of these infants through a follow-up study of extremely low birth infants (ELBWIs) at four to eleven years of age. Methods A follow-up study was carried out in all ELBWIs who were born between January 2000 and December 2009 in five hospitals of Beijing area. The study was conducted from May 2011 to August 2013. Clinical data of these ELBWIs were collected. Development of those ELBWIs was measured in the Peking Union Medical College Hospital, including physical, mental and motional development. Their cardiopulmonary functions were also examined. The incidence and treatment of disease in each system was analyzed, especially the incidence of severe complications. Descriptive statistical analysis was performed. Results (1) A total of 48 ELBWIs were followed up, with 24.4 to 34.0 weeks of gestation at birth, averaging (29.1±2.4) weeks. The birth weight of those ELBWIs was 700-900 g, with an average of (895±68) g. Among the 48 ELBWIs, 36 (75.0%) preterm infants were delivered for maternal gestational hypertensive disorders. Thirty-nine cases (81.2%) were small for gestational age. Those ELBWIs at 4.0-10.6 years of age were followed up, with an average age of (5.6±1.8) years. Thirty-six cases (75.0%) were followed up at clinic visits, and the other 12 cases (25.0%) were followed up through telephone calls. (2) Among the 48 cases, 31(64.6%) had lower weight, and 28(58.3%) had lower height than the average level. Fourteen children (29.2%) had physical retardation, among whom, seven cases had lower height, one case had lower weight, and six cases had both lower weight and height by 10 percentile. (3) Among the 48 cases, 42 cases (87.5%) had neonatal respiratory distress syndrome, 11(22.9%) had bronchopulmonary dysplasia, and 3(6.3%) had bronchial asthma. During the follow-up, 28 cases underwent ventilatory function tests. Moderately impaired pulmonary function was found in four cases (14.3%) ,mildly impaired pulmonary function in six cases (21.4%) and the pulmonary function was almost normal in the other 18 cases (64.3%). (4) Among the 48 cases, 10(20.8%) had patent ductus arteriosus, 1(2.1%) had atrioventricular block, and another case (2.1%) had ventricular premature beats and supraventricular tarchycardia. Two cases (5.6%, 2/36) had mildly dilated coronary sinus. (5) Six cases (12.5%) had intracranial hemorrhage of level Ⅲ-Ⅳ, and with no sequelae after treatment. Four cases (8.3%) were diagnosed as cerebral palsy, and one case (2.1%) as epilepsy in early childhood. (6) Mental development assessment was performed in 25 cases. Among them, two cases of cerebral palsy had mild or moderate mental retardation, four cases had border intelligence, and the other 19 cases had normal intelligence. (7) During hospitalization, sepsis occurred in three cases (14.6%), necrotizing enterocolitis in six cases (12.5%), and meningitis in one case (2.1%). All those cases were cured. (8) Among seven cases (14.6%) of retinopathy of prematurity, three cases received laser treatment, the other four cases improved after observation. None of them had visual impairment. One case (2.1%) had hearing impairment during follow-up. (9) Two years after discharge, 13 cases (27.1%) were rehospitalized for one to five times, with an average of (1.0±0.4) times. Eleven of the cases were rehospitalized for respiratory infections, and two cases for hernia or dermal hemangioma, respectively. Conclusions The incidence rate of development retardation in ELBWIs is high in this area. Cerebral palsy may occur in ELBWIs without intracranial hemorrhage. Treatment strategies should be further established to improve the development retardation, reduce severe complications and sequelae, and to improve the quality of life of the children. Key words: Infant, extremely low birth weight; Follow-up studies